Detent



Oct- 22, 1963 J. D. VERMEULEN DETENT Filed May 3, 1961 INVENTOR .Jo/wv 0. rzknuumg Q M/JW United States Patent 3,167,547 DETENT John D. Vermeulen, Kalamazoo, Mich, asslgnor to The New York Air Brake Company, a corporation of New Jersey Filed May 3, H61, Ser. No. 167,379 3 Claims. (Cl. 74527) This invention relates to impositive or yielding detents.

The object of the invention is to provide a simple and inexpensive detent for a reciprocable member that is relatively free of wear and binding and that may be unlatched in either of the two directions of motions of the member with the same force.

The preferred embodiment of the invention will be described with reference to the accompanying drawing whose single FIGURE shows a conventional four-position sliding plunger directional control valve incorporating the improved detent.

Referring to the drawing, the directional control valve includes a housing containing inlet and exhaust ports 1 and 2, respectively, a pair of motor ports 3 and 4 that communicate with the chambers 5 and 6, respectively, and a hollow valve plunger 7 that controls flow to and from the motor ports. The plunger 7 has a neutral or hold position (illustrated in the drawing) in which each motor port is isolated from the other three ports, a second operative position to the right of the neutral position in which motor port 3 is connected with the inlet port it and the motor port 4 is connected with the exhaust port 2, a third operative position to the left of the neutral position in which the connection between the motor ports and the inlet and exhaust ports is reversed, and a fourth or float position to the left of the third position in which all four ports are interconnected.

At its left end, the valve plunger 7 is provided with the detent 8 of the present invention. The detent comprises a circular sleeve 9 that is attached to the housing of the directional control valve and contains a pair of collars 11 and 12 that are slidable along its internal surface. These collars 11 and 12 are biased toward each other by a pair of coil compression springs 13 and 14 that exert nearly equal forces, and a snap ring 15 mounted in an annular groove formed in the surface of sleeve 9 limits the movement of each collar in the direction of the other. The opposing ends of collars l1 and 12 carry frusto-conical cam surraces 16 and 17 that engages the opposite sides of a series of detent balls 18 and these cam surfaces are arranged to urge the balls radially inward toward a central circular cylindrical member 19 that is coaxial with the collars and the sleeve 9. This member 19 is threaded into the left end of valve plunger 7 and is provided with four longitudinally spaced reduced diameter ball-receiving portions 21-24 that are so positioned that one portion is brought into alignment with the series of balls in each of the four operative positions of the plunger 7.

The conical angles of the cam surfaces 16 and 17 are equal and, since both of the collars 11 and 12 are slidable within sleeve 9, the detent is unlatched with equal forces in both directions of movement of plunger 7. The conical angle of the cam surfaces is so chosen that the collars 11 and 12 engage both the balls 18 and the snap ring 15 whenever the balls are resting in one of the portions 21-24. Because of this, the snap ring 15, in conjunction with the portions 21-24, serves to fix in space the locations of the detented positions of plunger 7.

As stated previously, the drawing and description relate only to the preferred embodiment of the invention. Since changes can be made in the structure of this embodiment without departing from the inventive concept, the following claims should provide the sole measure of the scope of the invention.

What is claimed is':

l. A detent comprising a sleeve; a central cylindrical member located in and coaxial with the sleeve, the member being movable longitudinally of the sleeve; a pair of collars located within the sleeve and encircling the central member, the collars being slidably longitudinally of the sleeve relatively to the sleeve and the central member; stop means carried by the sleeve and interposed between the collars for limiting the movement of each in the direction of the other; a circular series of detent balls surrounding the central member and located between the adjacent ends of the two collars; opposed cam surfaces carried by the adjacent ends of the two collars and arranged to engage the balls and urge them inward toward the central member; spring means reacting between the sleeve and the collars for urging each collar towards the other; and at least one ball-receiving groove in the outer surface of the central member, the parts being so dimensioned that the collars engage both the balls and the stop means when the balls are resting in the ball-receiving groove.

2. A detent comprising a circular sleeve; a circular cylinder located within and coaxial with the sleeve, the cylinder being movable longitudinally of the sleeve; a pair of collars located within the sleeve and encircling the cylinder, the collars being guided for sliding move ment by the sleeve relatively to it and to the cylinder; an annular stop carried by the sleeve and located between the two collars for limiting the movement of each in the direction of the other; a circular series of detent balls surrounding the cylinder and interposed between the adjacent ends of the two collars; frusto-conical cam surfaces carried by the adjacent ends of the two collars and arranged to engage the balls and urge them inward toward the cylinder; a pair of coil compression springs surrounding the cylinder, each spring reacting between the sleeve and one collar for urging it toward the other collar; and at least one reduced diameter ball-receiving groove in the outer surface of the cylinder, the parts being so dimensioned that the collars engage both the balls and the annular stop when the balls are resting in the ball-receiving groove.

3. The detent defined in claim 2 in which the conical angles of the two frusto-conical cam surfaces are equal.

References Cited in the file of this patent UNITED STATES PATENTS 375,200 Ross Dec. 20, 1887 891,800 Enrico June 23, 1908 2,329,182 Boynton Sept. 14, 1943 2,451,730 Greenlee Oct. 19, 1948 

1. A DETENT COMPRISING A SLEEVE; A CENTRAL CYLINDRICAL MEMBER LOCATED IN AND COAXIAL WITH THE SLEEVE, THE MEMBER BEING MOVABLE LONGITUDINALLY OF THE SLEEVE; A PAIR OF COLLARS LOCATED WITHIN THE SLEEVE AND ENCIRCLING THE CENTRAL MEMBER, THE COLLARS BEING SLIDABLY LONGITUDINALLY OF THE SLEEVE RELATIVELY TO THE SLEEVE AND THE CENTRAL MEMBER; STOP MEANS CARRIED BY THE SLEEVE AND INTERPOSED BETWEEN THE COLLARS FOR LIMITING THE MOVEMENT OF EACH IN THE DIRECTION OF THE OTHER; A CIRCULAR SERIES OF DETENT BALLS SURROUNDING THE CENTRAL MEMBER AND LOCATED BETWEEN THE ADJACENT ENDS OF THE TWO COLLARS; OPPOSED CAM SURFACES CARRIED BY THE ADJACENT ENDS OF THE TWO COLLARS AND ARRANGED TO ENGAGE THE BALLS AND URGE THEM INWARD TOWARD THE CENTRAL MEMBER; SPRING MEANS REACTING BETWEEN THE SLEEVE AND THE COLLARS FOR URGING EACH COLLAR TOWARDS THE OTHER; AND AT LEAST ONE BALL-RECEIVEING GROOVE IN THE OUTER SURFACE OF THE CENTRAL MEMBER, THE PARTS BEING SO DIMENSIONED THAT THE COLLARS ENGAGE BOTH THE BALLS AND THE STOP MEANS WHEN THE BALLS ARE RESTING IN THE BALL-RECEIVING GROOVE. 